There's really no difference between a digital camera and a film camera other than the fact that you can change the ISO setting without having to replace the film. That gives you a much wider range of light values ie, from barely light enough to see by to full sunshine on snow. It also means that you can use the ISO number as a third parameter when setting the exposure so, if you want to take an action photo in poor light, you can wind the ISO up to values you never dreamed of with film the drawback being the photos can get "noisy". Whenever I change my camera I take photos using all the ISO settings, compare the results and then decide what ISO value to set as normal maximum (you can usually limit the upperlimit used by the camera on auto) knowing that I can exceed if if desperate.